This program concerns integrated laboratory and clinical studies of cardiac muscle and its metabolism and blood flow in normal and diseased states. Blood flow in the human myocardium will be studied with direct (thermal dilution) and indirect (indicator washout) techniques and correlated with ventricular performance. Ventricular performance will be measured with both invasive and noninvasive techniques. Cardiac metabolism will be studied in intact man and isolated preparations and will range from analysis of the effect of various carbohydrates on metabolism to studies of amino acid exchange and protein synthesis and degradation within the cardiac cell.